EVIDENCE THAT ENDOTOXIN IS THE CYCLIC 3'-5'-GMP-PROMOTING FACTOR IN ERYTHROPOIETIN PREPARATIONS

  • 1 January 1979
    • journal article
    • research article
    • Vol. 93  (1) , 25-31
Abstract
Since Ep [erythropoietin] preparations are contaminated with endotoxin [etox], the possibility that the latter might be the factor in crude Ep, which increases c[cyclic]GMP levels in rat fetal liver cells, was examined. [Escherichia coli] etox produced a striking elevation of cGMP in rat fetal liver cells without affecting cAMP levels or heme synthesis. Absorption with Limulus lysate of more than 99% of the etox in a crude Ep preparation caused a parallel decrease in the cGMP-promoting activity without reduction of heme synthetic potency. Etox is the component of crude Ep which increases cGMP levels in rat fetal liver. The precise role of elevated cGMP in the action of etox on cells and the universality of this effect are unknown.